Question

A customer forgets a 4-digit code for an automatic teller machine (a.T.M.) in a bank. However, he remembers that this code consists of digits 3, 5, 6 and 9. Find the largest possible number of trials necessary to obtain the correct code

Answer 1

Answer:

24 Trials

Step-by-step explanation:

A customer forgets a 4-digit code for an automatic teller machine (a.T.M.) in a bank. However, he remembers that this code consists of digits 3, 5, 6 and 9. Find the largest possible number of trials necessary to obtain the correct code

Code consist of 4 digits

3 , 5 , 6 & 9

as code is of 4 digits & digits are also 4 so there is no repetition  of digit

so 1st digit can be selected out of any 4 digits available

2nd digit can be selected out of any 3 digits available

3rd digit can be selected out of any 2 digits available

4th Digits is the remaining digit

so largest possible number of trials required = 4 * 3 * 2 * 1 = 24

24 Trials

Generally ATM get blocked after 3 wrong trials so would not recommends for trial . Better to Get new ATM passcode